Calculating device



Nov. 4, 1930. J. R M NALLY 1,730,494

CALCULATING DEVICE Filed Sept. 15, 1928 tot Patented Nov. 4, 1930 PATENT FFICE JOHN R. MCNALLY, OF RALEIGH, NORTH CAROLINA GALGULATIN G DEVICE Application filed September 15, 1928.

This invention relates to calculating devices and it is an object of the invention to provide a device or" this kind comprising members adapted to be superimposed one above the other, each of said members having a predetermined identity, said superimposed members combining to produce tli value with which the desired calculation or computation is to be made, said superimposed members also being provided with means to readily indicate the desired result of such calculation or computation.

The invention also has for an object to provide a device of this kind en'ibodying means whereby is materially reduced the work of multiplication and division and which embodies an arrangement whereby a limited number of products in multiplication are divided into parts that can be easily reassembled in forms to show many times the original number of products.

Another object of the invention is to provide two groups of computations, a selected computation of one group being adapted to be superimposed upon a selected computation of a second group, said selected computations coacting in a manner whereby the right portions of the products of the multiplicand when multiplied from 1 to 9 inclusive are brought into reading relation with the left hand portions of the products.

The invention consists in the details or" construction and in the combination and arrangement ot the several parts of my improved calculating device whereby certain important advanta es are attained and the device rendered simpler, less expensive and otherwise more convenient and advantageous for use, will be hereinafter more fully set forth.

The novel features 01" my invention will hereinafter be definitely claimed.

Serial No. 306,200.

Figure 2 is a view in plan of a plurality of cards of one group;

Figure 3 is a view in plan or" a plurality of cards of the second group.

As herein disclosed, my invention employs two groups A and B of cards oi: desired dimensions, the groua A being ninety-nine in number and numbered as at a atthe upper lett hand corner from 1 to 99, such number or indication a constituting the multiplicand or left portion thereof and also serving to identify the same. The group B of cards are one hundred and one in number, one being blank and the remainder being numbered consecutively from 00 to 99, the necessary indications Z) being also arranged at the upper left hand corner portion of the cards and serving to identity the cards.

Each of the cards in the group A is provided with forty-four computations c and c of the number or indication value a, said computations serving, when they are used as a definite group, to show the left hand por tion of each possible product of any other number when the number or indication value a is the left hand portion of the other number and the multipliers are from 1 to 9 inclusive.

The computations c and 0 are suitably spaced in accordance with successive valuations upon such card with a blank space Z interposed between the number or value indication a and the first computation 0 to the right of the number or indication a which is the product of the number or valuation a multiplied by 2. The computations 0 in succession are the product or the number or valuation a multiplied from 2 to 9 inclusive and adjacent computations c are spaced apart a distance to have interposed therebetween a computation or computations 0 which are equal to the computations c to the lei't thereof plus the successive increase by one to a value equal to the greatest possible computation.

lnother words, the computation 0 reading 306, which is the productof the number or valuation a, multiplied by 6 will have to the right thereof five computations c" suecessively increasing in value byone. Or, in

other words, the computation or computations 0 between adjacent computations 0 are of a number equal to one less than the value of the multiplier for the computation c to the left of such group or series of computations 0. V V

The computations c and c on each of the cardsof the group A give the left hand portion of each possible product formed by multiplying from 1' to 9 inclusive any multiplicand which has as its left hand portion the same number as the number or indication valuation a. V

The number or valuation a, the computations 0 and (2 together with the space cl, as herein disclosed, are arranged'on horizontal lines and the spacing is the same on all cards of the group. I do not Wish, however, to be understood as limiting myself to such horizontal arrangements asthese various computations or indications may otherwise be positioned with equal advantage.

Each of the cards of the group B, as hereinbefore stated, is successively numbered from 00 to 99 with one of the cards blank and the number or indication bis arrangedat the upper left hand portion of the card within a space to the right of a perforated or slotted space 6 and which perforated or slotted space 6, when a selective card of the group B is superimposed upon a selective card of the group A, permits the. numher or indication valuation a to be exposed therethrough with the number 7) of the'card of the group B immediately adjacent to said exposed number or indication valuation a and whereby the complete multiplicand is assembled, the number or indlcation a const1tuting the left portion of the multiplicand and arranged, and the slots 7 are positioned immediately to the left of the spaces in which are placed the computations gwhich in succession are the two right hand numbers of the product of the number I; multiplied successively by 2 to 9. The full product may be only one figure such as l for 2 times 2; or '54 for 2 times 27; or 110 for 2 times 55, but it is always written as two figures. If there is only one figure in the product, such as 2 or a it is written 02 or 04. If the product is or over, the left hand figure is omitted.

If the product of the multiplication from which a g computation is derived is 100 or over, the omitted right hand figure determines the location of the adjacent f slot. If

' the omitted figure is 1" the 7" slot will be cut so as to come over the first 0' computation for the same multiplier. If the omitted figure is 2, the 7 slot will be cut so as to come over the second 0 computations on the cards of groupA for the same multiplier, and so on. The value of the figures omitted from the full products used in making the g computations is recovered by cutting the f slots so that they will come over 0 computations on the cards of group A with an increased value equal to the omitted figures. The computations 9 are always placed, just to the right of the slots. 7

Presuming it is desired to multiply 5127 the card in group'A identified by the value indication 51 has superimposed thereupon the card from group B having the value indication b of 27. The value indication a of 51 on the card from the group A will then be exposed through the perforated or slotted I space 0 of said superimposed card, the value indication a constituting the left portion of the multiplicand and the value indication b constituting the right portion of the multiplicand whereby is readily provided thefull multiplicand of 5127. i

The left portions of the products of such multiplicand will be exposed in succession through the spaces f and the computation g to the right of such open spaces f will constitute the right portion of the product. For example, if the multiplicand 5127 is to be multiplied by 8 the eighth of such slotted spaces will give the product 41016 as indicated in Figure 1.

The groups A and B should be separately distinguished by some prominent distinguishing marks as indicated at h and the products of each of the cards 13 should be successively numbered, as at i, from 1 to 9 inclusive, said identifications being preferably arranged in brackets. As any one of the nine products can be used as often as desired, it is necessary to have only one of the numbers to be multiplied less than 10,000. By merelyadding the various given products of 5127 or any number less than 10,000, such'number could be giultiplied by 98796879 or any other numer. 7 When a card of the group B is superimposed upon a selected card of group A nothing will be visible on such superimposed card of group B except the completed multipli- By using nine hundred and ninety-nine cards in group A and one thousand and one cards in group B, such set can be used the 1 cand and its eight products and the identities in brackets designating each product.

same as above except that the right portions of the products of each of the cards of group B will be the three right hand figures of the product. A set such as this canbe used to multiply any number less than one million.

To multiply 5127 by 7989 the products of the cards show as follows:

(5) (6) 7) 5127, 10254, 15381, 20508, 25535, soveaasssailoieiema You then put down on the adding machine or otherwlse and add the proper products as follows:

To divide the operation is just the reverse of multiplication. For example, if we are to divide 40959603 by 5127 the s veral operations will be as follows:

In division more work is saved than in multiplication because it eliminates trial to see how many times the divisor will go into the dividend. A glance at the eight products given on the superimposed selected cards 01" each group will show which of the products is the proper one to use. The de vice reduces the work in multiplication to the necessary addition and in division to the necessary subtraction.

I claim A calculating device of the character described comprisin in combination a card having a partial key number positioned thereon and a plurality of numbers constituting partial products of said partial key number and an apertured card adapted to be superposed on said first card, said apertured card having a key number aperture therein adapted to expose the partial key number therethrough and also having the remainder of the key number positioned thereon adjacent said key number aperture, the remaining apertures of said card having numbers positioned adjacent thereto constituting multipliers of said key number, said remaining apertures being disposed about said apertured card whereby to expose therethrough selected numbers of said first card, said selected numbers constituting partial products of the key number, said apertured card having numbers adjacent each aperture, said latter numbers when combined with said partial proclucts completing the product of the key numher by the multiplier.

In testimony whereof I hereunto afiix my signature.

JOHN R. MGNALLY. 

